In the rapidly advancing semiconductor manufacturing industry, complementary metal oxide semiconductor (CMOS) FinFET devices may be used in many logic and other applications and are integrated into various different types of semiconductor devices. FinFET devices typically include semiconductor fins with high aspect ratios in which the channel and source/drain regions for the transistor are formed. A gate is formed over and along the sides of a portion of the semiconductor fins. The increased surface area of the channel and source/drain regions in a FinFET results in faster, more reliable and better-controlled semiconductor transistor devices.
Current FinFET technology, however, has challenges. For example, the channel is usually formed from the bulk substrate and is susceptible to a channel punch-through effect at the bottom of the transistor. Channel punch-through is a condition in which the depletion layers of the source and the drain connect to each other through the substrate even at equilibrium. At low gate voltages, the punch-through current is injected through the saddle point of the intrinsic potential into the drain region by the electric field from the drain. The effect is premature breakdown of the FinFET.
As such, an improved fabrication method and structure for a FinFET device continue to be sought.